SO 有很多文章提到了这个错误代码:

SO has many articles mentioning this error code:

FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream...

这可能意味着此错误消息或多或少是无用的.

That probably means that this error message is more or less useless.

该消息告诉我们，由于某种原因，FastCGI 处理程序不喜欢它发送的任何内容.问题是有时我们不知道原因是什么.

The message is telling us that the FastCGI handler doesn't like whatever it was sent for some reason. The problem is that sometimes we have no idea what the reason is.

所以我要重申这个问题——我们如何调试这个错误代码?

So I'm re-stating the question -- How do we debug this error code?

考虑我们有一个非常简单的站点，只有 phpinfo.php 文件的情况.另外还有一个非常简单的nginx配置，如下:

Consider the situation where we have a very simple site, with just the phpinfo.php file. Additionally, there is a very simple nginx config, as follows:

server {
    server_name testsite.local;

    root /var/local/mysite/;

    location / {
        index index.html index.htm index.php;
    }

    location ~ .php$ {
        include /etc/nginx/fastcgi_params;
        fastcgi_pass  fastcgi_backend;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    }
}

我们如何才能准确地看到发送到脚本的 fastcgi_params 的输出/日志?

我们如何才能看到实际的错误消息? 就我而言，我使用的是 php-fpm.日志中没有关于此错误的信息.日志不会为此错误附加任何行.php-fpm 有详细模式吗?

How can we see the actual error message? In my case, I'm using php-fpm. It has no info in the log about this error. The logs do not append any rows for this error. Is there a verbose mode for php-fpm?

/var/log/php-fpm/error.log
/var/log/php-fpm/www-error.log

我已尝试在 php-fpm.conf 文件中进行设置

I've tried to set this in the php-fpm.conf file

log_level = notice

在 php-fpm.d/www.conf 文件中:

and this in the php-fpm.d/www.conf file:

catch_workers_output = yes